A lenticular array is required to image a dichroic stripe filter onto a charge coupled device (hereinafter CCD) chip for CCD cameras. Such a camera is described, for example, in U.S. Pat. No. 4,318,123. The desired periodicity of the array is about 20-100 microns, depending on the design of the CCD chip and the geometry of the dichroic filter associated with the chip, and the focal length is about 0.5 millimeter. The tolerances required are very stringent since the array must image the periodic filter structure exactly onto the periodic CCD chip. Variations in alignment will cause crosstalk and thereby reduce the resolution of the array. The array also must have a minimum of stray light, since stray light impacting the CCD chip limits the ability of the chip to obtain correct green, red, and blue color electronic signals.
Thus ideally the array must have a series of lenses with the exact same contour, and a minimum of area between the lenses which will diffract light.
The manufacture of a durable metal master, which can be used to cast or hot-press a series of plastic lens arrays which can meet these criteria, is very difficult and has not been able to be done on a regular basis using conventional techniques up until now. Thus, I have sought a process which is amenable to mass production but will have the perfection and uniformity desired using state of the art technology.